Funnily enough, it means something has a lot of chromeon it, not silver-coloured or platinum! The instance in which it is most frequently used is when one refers to a thugged out car's rims as being "chromed out" due to their chrome composition.

CEO of Mozilla: You there in the cubicle! Get on copying this new "Google Chrome" in every aspect except speed and ease of use and slap our logo big and bold on the home page! I want Firefox to be Chromed Out!